It is well known that certain guanidine derivatives of tert-carbinamines possess antihypertensive (hypotensive) activity. Specific examples are tert-alkyl cyanoguanidines such as 1-tert-amyl-3-cyanoguanidine as described in S. M. Gadekar, S. Nibi, and E. Cohen, J. Med. Chem., 11 811 (1968); and various derivatives of tert-alkyl guanidines such as tert-butyl guanidine, as described in J. H. Short, C. W. Ours, W. J. Ranus, Jr., J. Med. Chem., 11 1129 (1968).
However, urea derivatives are not represented in comprehensive discussions of antihypertensive agents. Such comprehensive discussions include W. T. Comer and A. W. Gomoll, Medicinal Chemistry, Third Edition, A. Burger, Wiley-Interscience, New York, 1970, pp. 1019-1064; and Medicinal Chemistry, Volume 7, "Antihypertensive Agents" , E. Schlittler, Academic Press, New York, 1967. The urea-derivative compounds of this invention provide effective treatment of hypertension, yet differ structurally and chemically over antihypertensive agents currently known.